1. Field of the Invention
The present invention relates generally to a magazine rack system utilized in assembly or processing of flat articles such as printed circuit boards or the like. Specifically to a magazine rack system for such articles in which a size of a portion for holding an individual article as well as a positional alignment of the magazine rack on a transport system, such as a chain conveyer, may be automatically adjusted.
2. Description of the Related Art
Various types of magazine rack systems having width adjustability for handling flat articles during assembly or processing have been proposed. Most commonly, a system in which force is applied directly to a movable plate which determines the accommodating width of the rack, and thereby the movable plate is moved to a desired width. In order to secure the movable plate at the desired width during subsequent use of the rack, a fixing mechanism, such as a screw fastening mechanism or the like is employed. In attempting to implement automatic control of such a rack as described above, an overall size of the rack, movable plate, fixing mechanism and control assembly becomes large and unwieldy rendering the assembled magazine rack uneconomical, complex and generally impractical.
On the other hand, automatically controlled magazine racks have been proposed, for example in Japanese Utility Model Application Nos. 64421-1990, 120272-1990 and 41244-1991, in which it is possible to easily and correctly move the movable side plate to control the accommodating width by applying rotational motive power thereto in one point fashion. However, according to the construction of these types of magazine racks, fine adjustment of rack size after the movable plate has been moved to the vicinity of a target position is extremely difficult, often necessitating that one worker hold a workpiece or measure for gauging size while a second worker performs fine adjustment of width control manually. Thus a considerable number of steps are necessary for rack adjustment operations.
In addition, when racks must be changed frequently during work operations, such as a part mounting line or the like, such adjustment must be performed repeatedly each time a rack is changed, consuming man hours and raising production expenses while reducing efficiency.
Also, in the above-described type of rack, as in the previously described rack, implementing automatic control causes an overall size and complexity thereof to become large and unwieldy rendering the magazine rack uneconomical, and impractical.
Further, according to widespread implementation of factory automation (FA) and computer integrated manufacturing (CIM), it is desirable to mount such a magazine rack as described above to a moving conveyer, such as a chain conveyer system.
When utilizing such a conveyer system for a specific production process, a spacing and alignment of the magazine rack in relation to the conveyer, as well as in relation to other magazine racks on the conveyer line is necessary. This operation may be effected by temporarily holding the magazine rack at an adjustment position while lateral adjustment of the spacing of the rack and adjustment of the alignment of the rack position in relation to the conveyer line, is made. Japanese Utility Model Application No. 10040-1992 (one of the applications on which applicant's claim for foreign priority benefit is based) discloses one such example of an adjustable magazine rack with an automated system for carrying out rack adjustment, however, this system is bulky and full automation of all processes is not provided.